Download Lecture: “Cancer Treatments”

Biology 207
Biology of Cancer
Lecture 21 and 22: “Cancer Treatments”
Spring 2004
Readings: King Chap. 13; Breast cancer microarrays (figures):
http://genome-www.stanford.edu/breast_cancer/sbcmp/figures.shtml from article by Perou et al.
(1999) Proceedings of the National Academy of Sciences 96:9212-9217 available from JSTOR,
Milne library.
Outline:
1. Overview of cancer treatments
2. Cancer specific and stage-specific treatments
3. Advances: surgery, radiation treatments
4. Chemotherapy
5. Individualized treatments/microarrays
Lecture: “Cancer Treatments”
1. Overview of cancer treatments
Major treatment approaches
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surgery
radiation therapy
chemotherapy
bone marrow transplant
hormone therapy
Cancer in situ:
surgery, follow-up radiation or chemotherapy?
Larger in situ tumors:
surgery + radiation or chemotherapy
Metastatic cancer:
surgery + chemotherapy
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2. Cancer-specific and stage-specific treatments
Rationale:
Each cancer type is different and may respond to different treatments; cancer is
diagnosed at various stages in different individuals. Thus, it makes sense to have
different treatment options for each cancer.
examples:
bone marrow transplant: leukemias
radiation: cervical, esophageal, oral cancers
chemotherapy: Burkitt’s lymphoma, Hodgkin’s lymphoma, Acute Lymphocytic
Leukemia, testicular cancer
hormone-based treatments: organs that produce or receive hormonal signals:
tamoxifen (anti-estrogen)--breast cancer;
anti-androgen therapies--prostate cancer
3. Advances: surgery, radiation treatments
Advances in surgery
 better imaging to locate tumors
 less drastic surgeries: lumpectomy
 reconstruction
 new ways to determine if cancer was removed
 shrink tumors before surgery
Advances in radiation treatments
 specialized machines
 treat localized regions
 implant options
 localized treatment reduces toxic side effects
 different particles used in treatments
 better calculations of radiation doses received by tissues
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4. Chemotherapy
Questions/Issues to be considered:
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How do chemotherapeutic drugs work (major classes)?
Toxicity/side effects
Drug resistance
Combination therapies
Sources of new drugs
Drug testing/clinical trials
MAJOR CLASSES OF CHEMOTHERAPEUTIC DRUGS
1. Antimetabolites interfere with DNA synthesis.
examples: Methotrexate, fluorouracil, hydroxyurea
2. DNA damaging agents:
--alkylating agents
--inhibitors of DNA enzymes
examples: nitrogen mustard, cisplatin, etoposide
3. Plant products that disrupt cell division
examples: vinblastine, taxol
How do these drugs kill the cancer cells?
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By “starving” them of raw materials for copying DNA.
OR 2. By damaging their DNA (or not repairing damage) and triggering
apoptosis (cell death).
OR 3. By halting cell division.
Why don’t the drugs kill normal cells?
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Most normal cells don’t divide frequently.
Normal cells that divide frequently are subject to the chemicals, esp. blood cells,
intestinal epithelial cells
Toxic side effects due to killing of these normal cells
intestinal cells: nausea, vomiting, diarrhea
blood cells: anemia, lack of blood clotting, immunosuppression
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Thus drug doses constantly adjusted to balance cancer cell killing and toxicity.
Drug resistance--When cancer cells become altered so they no longer respond to the
drug.
Combination therapies--Use of two or three different drugs at the same time to
minimize the likelihood of drug resistance.
Adjuvant chemotherapy--Refers to situations when chemotherapy is used along with
some other therapy (surgery or radiation therapy)
Screening for new drugs
5. Individualized treatments/microarrays
Pretesting tumors for drugs
Microarray technologies
Clinical trials
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